The present invention relates generally to compression gauges, and more particularly to an improved digital compression gauge adapted to evaluate both cylinder pressures and pressure variances through diagnosing a plurality of compression stroke pressures from each of the engine cylinders.
Digital compression gauges are used to evaluate pressures in cylinders of an internal combustion engine. These compression gauges are usually connected to one engine cylinder at a time to perform a pressure diagnostic of that cylinder. More specifically, a conventional compression gauge typically measures only the pressure generated during the last compressing stroke of the piston within the connected cylinder. By measuring the last compressing stroke pressure, the digital compression gauge estimates the overall pressure generated within the connected engine cylinder, hence completing that cylinder's diagnostic.
Although conventional digital compression gauges provide suitable estimates of cylinder pressures, they do not typically function to provide accurate measurements of cylinder pressures based upon a multitude of compressing stroke pressures. In other words, rather than basing the overall cylinder pressure measurement of one stroke pressure, it is desirable to measure multiple stroke pressures and use that information for engine diagnostic purposes. Multiple samplings of stroke pressures can enhance the cylinder diagnostics as it is unsound to assume that the initial compressing stroke of the pistons will produce the identical amounts of pressure as the last compressing stroke.
Further deficiencies of the conventional digital compression gauges lie in their inability to notify variances between the pistons' different compressing strokes, as such differences may reflect certain pressure conditions that may be adverse to engine operation. Such deficiencies arise as a result of the limited functionality of conventional gauges which only measure the very last compressing strokes of the pistons to perform cylinder diagnostics. Consequently, there is a need to improve existing compression gauges to facilitate functioning beyond their traditional role of merely estimating the overall cylinder pressures or measuring only the final compressions stroke.
Thus, there has long been a need in the automobile industry for a digital compression gauge that can provide better measurements of cylinder pressures through evaluating a multitude samples of compressing stroke pressures rather than merely estimating the same based upon one compressing stroke pressure. Moreover, there exists a need for a digital compression gauge which can also determine variances between compressing stroke pressures so as to further facilitate engine diagnostics.
The present invention addresses and overcomes the above-mentioned deficiencies of conventional digital compression gauges by providing an improved digital compression gauge which is adapted to evaluate cylinder pressures through measuring, storing and processing a plurality of compression stroke pressures from each of the engine cylinders. The improved digital compression gauge of the present invention is therefore functional to determine compression variants, e.g., pressure variances between the initial and last compressing stroke pressures from each of the engine cylinders, and can display such variances simultaneously on a single visual display. In this respect, not only does the present invention eliminate the need to resort to merely estimating the cylinder pressures, but it additionally provides an extra beneficial function of providing the above-described pressure variances which extends far beyond the traditional operational role of conventional compression gauges.